On Sat, 19 Jan 2008 14:30:12 +0000, Billy Burpelson wrote:
At the HAARP web site for the moon bounce experiment
(http://www.haarp.alaska.edu/haarp/mbann.html), they display a graph
that shows relative power of the incident and reflected signal versus
time. They show the transmitted signal at ~ -65 dB; they show the
reflected signal at ~ -77 dB.

Are they implying that the round trip path loss to the moon and back is
only ~ 12 dB???????

I think they're talking about the relative power *as measured at some
distant point*. If you're listening at a point say, 5,000 miles from the
transmitter in Alaska, you might hear the direct terrestrial signal from
Alaska at -65dB, and the lunar reflection at -77dB.

In other words, 12dB is the *difference* in path loss between the
lunar-reflected signal and the terrestrially-propagated signal.

(that difference still seems awfully small to me)

Another way of putting it... if there was a ham 200 miles away doing a
moonbounce transmission on 144MHz... his direct, terrestrially-propagated
signal at my location would be pretty weak... especially since his
antennas would be pointed up, at the moon, not down along the horizon...
so I would not be surprised if the *difference* between his
lunar-reflected signal and his terrestrial signal was a lot less than
252dB.